“线程中的异常”；AWT-EventQueue-0“；java.lang.UnsatifiedLink错误：testmydll.TestDLL.a（）I

我正在尝试从Java调用测试DLL

我正在使用

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import com.sun.jna.Library;
import com.sun.jna.Native;
import com.sun.jna.NativeLong;
import com.sun.jna.Platform;
import com.sun.jna.win32.StdCallLibrary;
import com.sun.jna.*;

该类被声明为

   class TestDLL {
   public native int a();
   public native int DoBeep();
   public native int PenniesToCoins();

   static { System.loadLibrary("PenniesLib");}

  // required to work with JDK 6 and JDK 7 ????????
  // I included this because it was in a few examples with the comment above
  // but it doesn't seem to make any difference 
  public static void main(String[] args){
 }
}

我在一个框架上有一个启动测试的按钮

void button1_actionPerformed(ActionEvent e) {
 int i;
 TestDLL t = new TestDLL();
 i= t.a();
 }
}

该程序在某个时间崩溃

      i= t.a();


Exception in thread "AWT-EventQueue-0" java.lang.UnsatisfiedLinkError:  testmydll.TestDLL.a()I
at testmydll.TestDLL.a(Native Method)
at testmydll.TestMyDLL.button1_actionPerformed(TestMyDLL.java:85)

我知道图书馆可以加载。将其名称更改为“PenniesLibX”会产生错误

我已经从一个Delphi程序中测试了这个DLL，并调用它

我已经用DLL导出查看器检查了导出的函数

a   0x00411ff4  0x00011ff4  1 (0x1) PenniesLib.dll  C:\WINXP\system32  PenniesLib.dll   Exported Function   
DoBeep  0x00411fe8  0x00011fe8  2 (0x2) PenniesLib.dll  C:\WINXP\system32\PenniesLib.dll    Exported Function   
PenniesToCoins  0x00411f7c  0x00011f7c  3 (0x3) PenniesLib.dll  C:\WINXP\system32\PenniesLib.dll    Exported Function   

非常感谢你的帮助

我将此重新写为

import com.sun.jna.Native;
import com.sun.jna.NativeLong;
import com.sun.jna.Platform;
import com.sun.jna.win32.StdCallLibrary;
import com.sun.jna.*;


 class TestDLL {
   public native int a();
   public native int DoBeep();
   public native int PenniesToCoins();

   static { System.loadLibrary("PenniesLib");}

 }


public class TestThisDLL {

  public static void main( String args[] ) {
      System.out.println("Start of DLL test");
      TestDLL t = new TestDLL();
      int i = t.a();
      System.out.println("DLL response is " + String.valueOf(i));
  }
}

Delphi DLL代码是

{ Copyright © 2001 Delphi 6 Developer's Guide Xavier Pacheco
   and Steve Teixeira }

{ DoBeep and a added  for testing}

library PenniesLib;
{$DEFINE PENNIESLIB}
uses
  SysUtils,
  Classes,
  PenniesInt;

function PenniesToCoins(TotPennies: word; CoinsRec: PCoinsRec): word; StdCall;
begin
  Result := TotPennies;  // Assign value to Result
  { Calculate the values for quarters, dimes, nickels, pennies }
  with CoinsRec^ do
  begin
    Quarters    := TotPennies div 25;
    TotPennies  := TotPennies - Quarters * 25;
    Dimes       := TotPennies div 10;
    TotPennies  := TotPennies - Dimes * 10;
    Nickels     := TotPennies div 5;
    TotPennies  := TotPennies - Nickels * 5;
    Pennies     := TotPennies;
  end;
end;

function DoBeep: word; StdCall
begin
    Beep;
    Result:=55;
end;

function a: word; StdCall
begin
    Beep;
    Result:=88;
end;

{ Export the function by name }
exports
  PenniesToCoins, DoBeep, a;
end.

---

您没有按照预期的方式包装本机库。事实上，您在问题代码中没有使用任何JNA。关键是必须调用Native.loadLibrary

您的Java代码应该如下所示：

import com.sun.jna.Library;
import com.sun.jna.Native;
import com.sun.jna.Platform;
import com.sun.jna.win32.StdCallLibrary;

public class TestThisDLL {
    public interface PenniesLib extends StdCallLibrary {
        PenniesLib INSTANCE = (PenniesLib) Native.loadLibrary(
            "PenniesLib", PenniesLib.class);
        int a();
    }

    public static void main(String[] args) {
        int value = PenniesLib.INSTANCE.a();
        System.out.println(value);
    }
}

---

请注意，我冒昧地假设您将在Delphi代码中将

Word

更改为

Integer

。由于Java没有无符号类型，而且16字节类型非常复杂，我认为32位有符号整数最有意义。

您有DLL的源代码吗？为什么main为空，以便更好地帮助您尽早发布SSCCE、short、runnable、compileable、，Swing Gui必须在上创建我已将Delphi源代码添加到postingI已将其作为非Swing程序重新编写我认为问题在于我天真地假设您可以轻松地从Java调用普通DLL。说明Java本机接口使用自己的命名约定，必须专门编写JNI DLL。有没有一种从Java调用标准DLL的简单方法？我很高兴听到这个消息，并感谢您的接受。我无法让我的Java JVM加载已编译的类，但我有理由相信这只是一个问题，因为我完全不知道如何运行Java。问题中的代码是对常见JNA示例的简单修改。